Orchard-heater type burner



Jan. 25, 1955 c. R. G1LMORE 2,700,419

ORCHARD-HEATER TYPE BURNER Filed Nov. 29, 1951 6 Sheets-Sheet 1 FIG. I

i o o 0 o INVENTOR. CLEMENT R. GILMORE ATTORNEYS Jan. 25,v 1955 c. R. GILMORE 2,700,419

ORCHARD-HEATER TYPE BURNER d Nov. 29, 1951 6 Sheet sssss et 2 2 CLEMENT R. GILMORE ATTORNEYS Jan. 25, 1955 c. R. GILMORE 2,700,419

ORCHARD-HEATER TYPE BURNER Filed Nov. 29, 1951 6 Sheets-Sheet 3 G OOQOOOOQOOH FIG. 5

IN V EN TOIIC. c LEMEi-JT a. canon:

BY 1,32 H-MZFEI Jan. 25, 1955 c. R. GILMORE 2,700,419

ORCHARD-HEATER TYPE BURNER Filed Nov. 29, 1951 6 Sheets-Sheet 4 FIG. 6

' INVENTOR. CLEMENT R. GILMORE Jan. 25, 1955 c. R. GlLMORE 2,700,419

ORCHARD-HEATER TYPE BURNER Filed Nov. 29, 1951 6 Shee'ts-Sheet 5 INVENTOR.

' CLEMENT R. GILMORE Jan. 25, 1955 c. R. GILMORE ORCHARD-HEATER TYPE BURNER 6 Sheets-Sheet 6 Filed Nov. 29, 1951 FIG. 8

INVENTOR.

EJJMEN'I' R. GILMORE E 31 a; H MJQ United States Patent 9 ORCHARD-HEATER TYPE BURNER Clement R. Gilmore, Shaker Heights, Ohio Application November 29, 1951, Serial No. 258,808

2 Claims. (Cl. 158-91) The prevent invention relates to oil burners and particularly to vaporizing type burners in which liquld hydrocarbon fuels are vaporized in a retort chamber, mixed with air and then burned. This application is a continuation-in-part of my co-pending application, Serial No. 239,119, filed July 28, 1951, which application, Serial No. 239,119, is, in turn, a continuation-in-part of my ctg-pending application Serial No. 225,215, filed May 8, 19 1.

In my copending application, Serial No. 239,119, filed July 28, 1951, I have disclosed a burner which provides for rapid recirculation of oil vapor and air over the surface of liquid oil within a retort chamber. As set forth in that case, it was discovered that the rate of oil vaporization and the capacity of the burner was materially greater than the vaporization rates and capacities of prior vaporizing or pot type burners of comparable size. The burner was also found to be very responsive to air and oil flow control. Of particular importance was the fact that the burner was able to effectively burn catalytic oils which have not heretofore been successfully utilized in the relatively inexpensive vaporizing or pot type burners.

In the employment of vaporizing burners under certain circumstances, a primary object is the elimination of smoke and the maintenance of efiicient combustion particularly at the higher stages of combustion. In such burners, cleanliness of the fire during ignition and at lower stages of combustion and augmentation of the rate of oil vaporization areof secondary significance. For instance, orchard burners, used to protect fruit against frost damage, are typically normal fire burners, that is, they are ignited at the onset of frost and after rising to normal fire they continue to burn at a constant level until their fuel is exhausted or until they are extinguished. Although these burners are smoky during their rise to normal fire, this feature in itself is not too objectionable because the smoke produced during the relatively short rise to full fire is quickly dissipated in the outdoor environment. However, prolonged smoking of these burners is very objectionable. The burners are typically dispersed in great numbers throughout large areas of. orchards or citrus groves, and continued smoking of a number of burners for several hours will raise a heavy smog in the neighborhood and will result in a local deposit of sooty carbon. This smoking is particularly objectionable in partially built up communities where homes and commercial buildings are in the vicinity of the groves.

I have discovered that a smokeless normal fire burner may be constructed by providing a chamber for the intermixture and reaction of oil vapor and air which contains gas-flow defining members to induce a recirculating flow of incoming air, oil vapor and the intermixtures and initial products of reaction thereof, entirely independently of any sweeping of the liquid oil surfaces by the recirculating gases, as will be more fully explained below. Not only does my invention eliminate smoking at normal fire but the ratio of fuel consumption to heat output is less than that of conventional burners of comparable size and cost. Because of this increased efliciency the present invention may be advantageously used in low cost heaters other than orchard heaters where smokeless normal fire performance and fuel economy are also important, such as. utility heaters, itove heaters or other flue type or contaminated air instal- 'ations.

2,700,419 Patented Jan. 25, 1955 Other objects and advantages of my invention will become apparent from an examination of the following specification and claims and the drawings in which:

Figure 1 is a side elevation in cross section of a burner embodying my invention.

Figure 2 is a section taken on line 2-2 of Figure 1.

Figures 3 and 4 are schematic illustrations of toroid paths of gas flow induced within the burner.

Figure 5 is a view of an alternative structure embodying the invention.

Figure 6 is a section taken on line 66 of Figure 5.

Figure 7 is a view of another alternative structure embodying the invention.

Figure 8 is a section taken on line 8--8 of Figure 7.

Figures 1 and 2 illustrate an embodiment of my invention adapted for use as an orchard heater. However, as mentioned above and as will become apparent, burners employing the principles of my invention may be used as utility heaters, stove heaters or other related heating installations by employing suitable housings and/or adding flame boxes, heat interchangers, stacks or other appropriate vapor-confining chambers or ducts beyond the high-fire end of the burner.

Figures 1 and 2 illustrate a burner comprising a perforated upstanding cylindrical wall 20 defining a chamber 21 and supported on a hollow base 22. The cham- 'ber 21 is separated from the reservoir space 23 by a wall 24 in which there is an opening 25. The upper end of the cylindrical wall 20 is preferably capped with an inwardly flanged cover 27 to define a somewhat narrowed upper opening 28 from the chamber 21. The wall 20 is perforated with a number of holes 30 to constitute a perforate zone designed to admit air for admixture, preliminary or intermediate reaction and final comgglstion with the oil vapors rising from the opening Suitably supported within the chamber 21 by the legs 31 is a stack or cylinder 32. The legs space the stack 32 from the wall 24 to form spaces or slots 33. Located longitudinally upwardly along the stack are additional slots 34 and 35. The top of the cylinder 32 is preferably capped by a cover 36 which may be hinged to the stack as at 37.

One or preferably a series of recirculating rings 40 are provided in surrounding and spaced relation with the stack 32. The rings 40 may be removably supported in position by depending legs and radial spacers (not shown) or, as illustrated, they may be supported by short radial arms 41 fixed to the sides of the stack 32. Although the exact positioning of the rings is-not critical, it has been found preferable that each ring be positioned slightly below a row of the perforations 30. Also, it is preferable that a ring 40 be positioned just below each of the slots 34 and 35 and that each of these slots be on a level with one of the rows of holes 30.

In this illustrated embodiment of my invention oil is supplied to the fuel space 23 through a filler hole 50 which is threaded to receive a plug 51. A slot orflat '52 may be provided on the plug 51 through which outside air is admitted to the vapor generating upper portion of the chamber 23. When it is desired to cut off this air supply to shut ofi the burner, the plug 51 may simply be turned in until the slot 52 is blocked from the outside air. For convenient lighting of the burner, a rod 55 may be welded to the bottom end of the plug 51. Secured to the lower end of the rod is a wad or ball 50 of any suitable oil absorbent and preferably fireproof wicking material such as asbestos fiber. When the reservoir has been filled with oil to the level illustrated, the wad 50 on the removed plug may be conveniently lit with a match or by holding it over another burner and then inserted through the filler hole 50 to gnite the oil, whereupon the plug 51 may be inserted in posltlon.

The arrows in Figure 1 illustrate the gaseous fluid flow within the chamber 21 at normal or full fire. Air drawn in through the perforations 30 moves toward the stack 32. Oil vapors rising from the opening 25 are drawn toward the outer wall 20 through which the incoming air is being supplied. The flow of the incoming air and oil vapor in turn induces a circulating .or-wrapping flow around each of the rings 40. Toward the center of the burner there is a general flow of the gases toward the oil vapor source while toward the sides of the burner the general vapor movement is toward the firing end of the burner.

It will be noted that the disclosed structure is designed to function as a natural draft burner, no air fan or pump being employed. Nevertheless the pattern of flow described above will quickly and positively establish itself as the burner rises to normal fire. Air flames which extend within the chamber 21 from the perforations do not veer upwardly as'would be expected but extend horizontally toward the center of the chamber.

As the gases within the chamber 21 circulate tightly around the rings and move loosely down through or adjacent to the stack 32 and up past the perforations 30, the air and oil vapors and preliminary products of reaction between the two become intimately mixed. The exact nature of the burners action is not clear but the recirculation or wrapping of the gases and the passage of the gaseous intermixture and products of reaction across the paths of the incoming air supply efiect striking results in burner performance, particularly in the elimination of free carbon and smoke. Carbon or tar deposits within the burner are greatly reduced in comparison with previous burners and under normal field conditions are eliminated entirely.

The stack 31 and rings 32 are special and preferred examples of the various shapes of baffles or flow inducing members which may be employed to effect the recirculating flow of gases described above. The toroid path of gas fiow induced by each ring 40 is schematically illustrated in Figure 3. The path illustrated in Figure 4 is substantially that induced by the stack 31 and is also, topologically speaking, toroid. Other variations in the geometric cross section of the toroid paths have been found suitable, for instance it is advantageous in some installations to block the space between the lower ring 40 and the stack 32. Truncated cones, rings of circular cross section and similar open-centered or endless annular shapes may be substituted for the illustrated rings and cylindrical stacks which, however, have been chosen for illustration in combination because that specific organization of elements has been found to be most preferable. Any shape which will roughly define a closed or toroid section path for circulating gases within the chamber will significantly improve burner performance. Obviously, shapes which are opencentered and endless but not circular, such as square frames or box-sections, may also be employed, although such shapes would not be peferred for use in the illustrated round chamber 21.

It will be understood that the present invention involves no sweeping of the hot recirculating gases directly over the surface of the liquid oil supply although, of course, incidental eddy currents may occur in the upper portion of the chamber 23. Even in embodiments of the invention utilizing other fuel sources equivalent to the pool of oil within the chamber 23, such as oil soaked wicking inserted in the opening 25 (suitable for oil stove installations), there will not be high velocity impingement and sweeping of the recirculating gases against the liquid oil. The central lower volume of the stack 32 will be substantially by-passed by the recirculating vapors. The present invention, therefore, embodies my discovery that recirculation alone within the oil vapor-air combining chamber will significantly improve burner performance entirely independently of any sweeping of the hot recirculating gases over the surface of the liquid oil.

Examples of the above described modifications are illustrated in Figures 5-8. In general organization, the structure illustrated in these figures is similar to that shown and described in the structure shown in Figures 1 and 2. However, in Figures 5 and 6, rings 60, similar to the rings 40 of Figures 1 and 2, are shaped as shallow truncated cones. Further, in Figures 5 and 6 the filler cap or plug 61 is preferably not slotted, and the chamber 63 is not vented. A wick 64 is provided supported by a sleeve 62, the wick extending into the opening 65, which is similar to the opening 25. The wick may be adjusted in the conventional manner by a serrated wheel 66 which may be rotated by a shaft 67 extending out through the side of the chamber 63. The wheel extends through a slot in the sleeve 62 to engage the wick 64. The wick 64 is in the form of a hollow tube of stiff fabric capable of supporting itself against collapse. If a flexible fabric is employed, an additional anti-collapse tube similar to that tube 62, but of reduced diameter, may be employed. Lack of venting of the chamber 63 tends to prevent at all times, including ignition, any occurrence of fire below the top of the wick. It will be understood that in this embodiment the provision of fuel within the pot proper arises not from vaporization of the oil pool within the chamber 63, but rather by vaporization of the oil from the top portion of the wick, to which top portion the oil is continually supplied by capillary action. In Figures 7 and 8 the general organization is again similar to that shown in Figures 1 and 2, except that the rings 70, upper and lower chambers 71 and 72, and stack 73 are square in plan view, as clearly seen in Figure 8. Further, the lower ring 70A may form a continuous projection from the lower portion of the stack 73, there being no gap between these members, as shown in Figure 7.

The modifications in the disclosed burner which I have suggested above will make it apparent that many vari ations in the burner illustrated in this application occur to those skilled in the art. My invention, there: fore, is not to be limited to its specifically illustrated embodiments, but is to be defined solely by the scope of the following claims.

What is claimedis:

1. In a liquid fuel burner, a retort chamber having the shape of a pot with an inner closed end and an outer open end, aperture means to admit air at a plurality of vertical and circumferential locations on the sidewalls of said retort chamber, means to generate fuel vapors below said retort chamber, an opening in said inner closed end of said retort chamber to admit vapors from said generating means into said retort chamber, baffle means within said retort chamber, said baffle means comprising ring means and means defining a central covered chamber having slotted sidewalls, said slots extending through said sidewalls, at least one of said slots being adjacent said inner closed end, at least one ring of said ring means being located between said central chamber and the sidewalls of said retort chamber, said at least one ring having a radially outer edge spaced from the sidewalls of said retort chamber and a radially inner edge spaced from the sidewalls ofsaid central chamber, the lowermost of said aperture means being operatively associated with said radially outer edge to direct incoming air along paths passing over and adjacent to said radially outer edge on the uppermost side of said at least one ring, whereby fuel vapors admitted into said retort chamber are induced to move upwardly toward said outer open end along continuous vertical paths at the vertical location of said bafile means solely through peripheral portions of said pot and a majority of said upwardly moving vapors will cross the paths of air admitted through said aperture means and a majority of the movement'of vapor air along sidewalls of said central chamber will be in a downward direction toward said inner closed end.

2. In a liquid fuel burner, a retort chamber having the shape of a pot with an inner closed end and an outer open end, aperture means to admit air at a pluralf ity of vertical and circumferential locations on the side: walls of said retort chamber, means to generate fuel vapors below said retort chamber, an opening in said inner closed end of said retort chamber to admit vapors from said generating means into said retort chamber, baflle means within said retort chamber, said baflle means comprising ring means and means defining a Central covered chamber having slotted sidewalls, said slots extending through said sidewalls, at least one of said slots being adjacent said inner closed end, at least one ring of said ring means being located between said central chamber and the sidewalls of said retort chamber, said at least one ring having a radially outer edge spaced from the sidewalls of said retort chamber, at least an other one of said slots being located immediately above said at least one ring, the lowermost of said aperture means being operatively associated with said radially outer edge to direct incoming air along paths passing over and adjacent to said radially outer edge on the pp m side of a d a east o e r n wh eby fii vapors admitted into said chamber are induced to'moye upwardly toward said outer open end along continuous vertical paths at the vertical location of said baffle means solely through peripheral portions of said pot and a majority of said upwardly moving vapors will cross the paths of air admitted through said aperture means and a majority of the movement of vapor air along sidewalls of said central chamber will be in a downward direction toward said inner closed end.

References Cited in the file of this patent UNITED STATES PATENTS 

